Surgical implants as used for bone fixation or specifically for spinal fixation often contain one or more longitudinal members, to which the bone fixation elements or, specifically in the case of spinal fixation, the pedicle screws are fastened and consequently are fixed with respect to one another in a longitudinal direction. For stiffening an implant as a whole, containing a plurality of longitudinal members, the longitudinal members are connected to one another by means of transverse connectors, which are attached transversely with respect to the longitudinal members between the latter.
Some devices for connecting longitudinal members within spinal column implants are already known from the prior art. These have the advantage that the implanted longitudinal members are considerably stiffened by the transverse connection by means of these devices. Thanks to the already known devices, it is also possible to implant the transverse connections at angles which deviate to a certain extent from a right angle.
Such a device for connecting longitudinal members is known for example from EP-A 0 836 836 to Richelsoph. The device disclosed therein for connecting longitudinal members within spinal column implants comprises a telescopic transverse connecting body with two bores for each receiving an insert, the two bores being provided at the opposite ends of the transverse connecting body. The transverse connecting body can be partly slipped over the longitudinal members running transversely with respect to the central axis of the connecting body.
A further connecting device of this kind is known from EP-A 0 778 007 to Pfaifer. This known device comprises a central body, a ring which can be pushed over the latter and a nut which can be screwed onto an external thread provided at the upper end of the central body. Transversely with respect to the longitudinal axis of the central body and transversely with respect to the central axis of the channel, a through-opening is provided in the central body for receiving a transverse rod. This transverse rod is received in a corresponding channel in the ring and fixed with respect to the device by clamping between the ring and nut.
A disadvantage of EP-A 0 778 007 to Pfaifer is that the longitudinal member can be arranged only within a small angular range, including right angles, with respect to the transverse connector.
The invention is intended to remedy this. The invention relates to a device for connecting rods and specifically also longitudinal members of spinal column implants, or else for connecting a rod to a further implant, for example to a bone anchorage element or a pedicle screw, with the following properties: simple handling; connection of longitudinal members which are not implanted in parallel; prevention of slipping of the rod connection after implantation; and making it possible for an implant as a whole to be very rigid, for example with longitudinal members that cannot twist after the fastening of the rod connections. Such a device may be used for releasably clamping and connecting a longitudinal member within a surgical implant in the body of a human or animal.